mm: vmalloc: check if a hash-index is in cpu_possible_mask

The problem is that there are systems where cpu_possible_mask has gaps
between set CPUs, for example SPARC.  In this scenario addr_to_vb_xa()
hash function can return an index which accesses to not-possible and not
setup CPU area using per_cpu() macro.  This results in an oops on SPARC.

A per-cpu vmap_block_queue is also used as hash table, incorrectly
assuming the cpu_possible_mask has no gaps.  Fix it by adjusting an index
to a next possible CPU.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 062eacf57ad9 ("mm: vmalloc: remove a global vmap_blocks xarray")
Reported-by: Nick Bowler <[email protected]>
Closes: https://lore.kernel.org/linux-kernel/ZntjIE6msJbF8zTa@MiWiFi-R3L-srv/T/
Signed-off-by: Uladzislau Rezki (Sony) <[email protected]>
Reviewed-by: Baoquan He <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Hailong.Liu <[email protected]>
Cc: Oleksiy Avramchenko <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions